Answer :
[tex]\begin{gathered} \text{let:} \\ x=\text{large tables} \\ y=\text{small tables} \end{gathered}[/tex]
A building code allows a maximum of 140 people in a meeting room, so:
[tex]15x+5y\le140[/tex][tex]\begin{gathered} \text{ There is one large table, so:} \\ x=1 \\ 15+5y\le140 \\ \text{Solve for y:} \\ 5y\le140-15 \\ 5y\le125 \\ y\le\frac{125}{5} \\ y\le25 \end{gathered}[/tex]